Circuit Code Research Articles

串联型双轨增强电磁轨道炮电路模拟

Based on the principle of electromagnetic railgun launch, a circuit model was developed and validated, the pulse forming units (PFU) and the progress of the railgun launch were included. The corresponding Pspice circuit code was developed to simulate the current of each pulse forming unit. Acceleration properties of the armature were also simulated by the Pspice analog behavioral modeling tools. The simulated railgun current and the armature velocity were 2.6% and 9.8% higher than the experiment results, i.e., the simulation and the experiment results were roughly consistent with each other. The model has provided valuable data which can directly benefit the design and operation of the series augmented railgun systems.

Design and Application of Vibration Signal Acquisition System Based on ATmega128 MCU

This paper introduces one method to design a vibration diagnosis device from several sides such as components choosing, circuit designing and soft programming. This device consists of ATmega128 MCU, acceleration transducer, TLC2543 and other peripheral components and it can conveniently acquire and analysis signal. The resource used to test the device was supported by Function Generator and amplified by Power Amplifier. The data was exported to PC and graphed by MatLAB application, and then made a comparison with the theoretical graph to prove the method validity. This design has simple circuit and small codes, but it can capture mechanical working state accurately, so it has preferably practical value and economic benefit.

Snakes, coils, and single-track circuit codes with spread $$k$$ k

The snake-in-the-box problem is concerned with finding a longest induced path in a hypercube $$Q_n$$Qn. Similarly, the coil-in-the-box problem is concerned with finding a longest induced cycle in $$Q_n$$Qn. We consider a generalization of these problems that considers paths and cycles where each pair of vertices at distance at least $$k$$k in the path or cycle are also at distance at least $$k$$k in $$Q_n$$Qn. We call these paths $$k$$k-snakes and the cycles $$k$$k-coils. The $$k$$k-coils have also been called circuit codes. By optimizing an exhaustive search algorithm, we find 13 new longest $$k$$k-coils, 21 new longest $$k$$k-snakes and verify that some of them are optimal. By optimizing an algorithm by Paterson and Tuliani to find single-track circuit codes, we additionally find another 8 new longest $$k$$k-coils. Using these $$k$$k-coils with some basic backtracking, we find 18 new longest $$k$$k-snakes.

Introduction to the Journal of Cryptographic Engineering

The mathematics, computer science and electrical engineering academic communities began paying attention to cryptography sometime in the mid-1970s. The fruits of the work that was then being performed at MIT and Stanford [1,2] now forms the backbone of communication security, including online shopping, logging into email servers and corporate VPNs, and many other activities we perform over the Internet or via cellular communication networks. The remarkable history of the development of cryptography during the last quarter of the last century consists mainly of fragments in several different books or in the memories of our colleagues. Yet in these 25–30years, just a handful of people in several universities and research centers in the US and Europe created a set of cryptographic algorithms and protocols that demonstrated the meaning and the measure of cryptographic strength [1–10]. The online security of billions of consumers now depends on the infrastructure developed according to these cryptographic principles. The story would not be complete, however, if we stopped thinking and talking about it right at this point. The invention of cryptographic algorithms and protocols, particularly public-key algorithms, digital signatures, hash functions and message authentication methods, was essential for the security of our computers, laptops, smart phones and servers. However, equally important are the hardware and software realizations for the platforms on which they run. There are some significant challenges in high-speed, small-space (circuit size or code space) implementations of

Shrapnel Generation from Recyclable Transmission Lines

The ultimate goal of this research is to understand how the recyclable transmission lines (RTL) fail and break apart following each power generating pulse under inertial-fusion-energy-type loading. Containing and collecting the resulting dust, debris, and shrapnel so that it may be repetitively reprocessed and recycled is an especially important step, among many others, to successfully operating a power plant. In this paper the current and the dynamic pressure pulse along the RTL are simulated with the Micro-Cap network circuit code. These results are used as inputs to the CTH shock physics code that characterizes the debris formation and containment wall impacts. These models were applied to represent different sections of the RTL at two resolutions. The following discussion addresses the full size nested cone RTL for a Z-pinch IFE power plant.

Energy deposition via magnetoplasmadynamic acceleration: II. modeling and performance predictions

A time-dependent, two-dimensional, axisymmetric magnetohydrodynamics code is employed to model, validate and extend the experimentally-limited performance characteristics of a gigawatt-level plasma source that utilized magnetoplasmadynamic (MPD) acceleration for gas energy deposition. Accurate modeling required an upgrade of the code's circuit routines to properly capture the pulse-forming-network current waveform which also serves as the primary variable for validation. Comparisons with experimentally deduced current waveforms were in good agreement for all power levels. The simulations also produced values for the plasma voltage which were compared with the measured voltage across the electrodes. The trend agreement was encouraging while the magnitude of the discrepancy is approximately constant and interpreted as a representation of the electrode fall voltage. Force computations captured the expected electromagnetic acceleration trends and serve as further verification. They also allow examination of the device as a very high power MPD thruster operating at power levels in excess of 180 MW. The computations offer insights into the plasma's characteristics at different power levels through two-dimensional distributions of pertinent parameters and identify design guidelines for effective stagnation temperature values as a function of the mass-flow rate.

Computing Binary Combinatorial Gray Codes Via Exhaustive Search With SAT Solvers

The term binary combinatorial Gray code refers to a list of binary words such that the Hamming distance between two neighboring words is one and the list satisfies some additional properties that are of interest to a particular application, e.g., circuit testing, data compression, and computational biology. New distance-preserving and circuit codes are presented along with a complete list of equivalence classes of the coil-in-the-box codes for codeword length with respect to symmetry transformations of hypercubes. A Gray-ordered code composed of all necklaces of the length is presented, improving the known result with length .

Single-track circuit codes

Single-track circuit codes (STTCs) are circuit codes with codewords of length n such that all the n tracks which correspond to the n distinct coordinates of the codewords are cyclic shifts of the first track. These codes simultaneously generalize single-track Gray codes and ordinary circuit codes. They are useful in angular quantization applications in which error detecting and/or correcting capabilities are needed. A parameter k, called the spread of the code, measures the strength of this error control capability. We consider the existence of STCCs for small lengths n/spl les/17 and spreads k/spl les/6, constructing some optimal and many good examples. We then give a general construction method for STCCs which makes use of ordinary circuit codes. We use this construction to construct examples of codes with 360 and 1000 codewords which are of practical importance. We also use the construction to prove a general result on the existence of STCCs for general spreads.

Some new circuit codes

Let n/spl ges/1 and suppose C=W/sub 0/,W/sub 1/,...,W/sub t-1/ is a list of t length n binary words. For 1/spl les/k/spl les/n we say that C is a length n, spread k circuit code if for every i,j with 0/spl les/i,j<t, d/sub H/(W/sub i/,W/sub i+1/)=1, d/sub H/(W/sub i/,W/sub j/)<k/spl rArr/d/sub c/(W/sub i/,W/sub j/)=d/sub H/(W/sub i/,W/sub j/) where subscripts are reduced modulo t, d/sub H/ denotes Hamming distance and d/sub c/ denotes the number of places between the two words in the list C. Codes of spread 2 are also known as snake-in-the-box codes. For given n and k, it is of interest to maximise the number of words in such a code, as this increases the resolution that can be achieved. We present a new construction for circuit codes, yielding many codes better than those previously known.

Using logic programming and coroutining for electronic CAD

We show how an extended Prolog can be exploited to implement different electronic CAD tools. Starting with a computer hardware description language (CHDL) several problems like digital circuit analysis, simulation, test generation, and code generation for programmable microprocessors are discussed. For that purpose the MIMOLA (machine independent microprogramming language) system MSS (MIMOLA hardware design system) is presented. It is shown that logic programming techniques have several advantages especially in the area of integrated circuit design. One of the main advantages is the small code size, which translates to easy maintenance. We make extensive use of two main features of standard Prolog and constraint logic programming, i.e., backtracking and the coroutining mechanism, to express Boolean constraints.

Time domain solutions to partial differential equations using SPICE

In this paper a method for using a time domain circuit code to solve partial differential equations is described. Rather than following the usual approach of developing a lumped-element circuit model, the partial differential equation is finite differenced in space and written in state variable form. The resulting system of coupled ordinary differential equations is then modeled by an array of coupled voltage dependent current sources connected to a string of capacitors. A preprocessor is used to write the network list in a form usable by the SPICE circuit analysis code. Examples for advection, diffusion, and electromagnetic propagation in one spatial dimension are given.

Projectile transverse motion and stability in electromagnetic induction launchers

The transverse motion of a projectile in an electromagnetic induction launcher is considered. The equations of motion for translation and rotation are derived assuming a rigid projectile and a flyway restoring force per unit length that is proportional to the local displacement. Linearized transverse forces and torques due to energized coils are derived for displaced or tilted armature elements based on a first order perturbation method. The resulting equations of motion for a rigid projectile composed of multiple elements in a multi-coil launcher are analyzed as a coupled oscillator system of equations and a simple linear stability condition is derived. The equations of motion are incorporated into the 2-D Slingshot circuit code and numerical solutions for the transverse motion are obtained. >

An external millisecond timer for the Apple Macintosh with applications to cross-modal lexical priming

The circuit and program described in this report allow researchers to use Macintosh personal computers to conduct research that requires timing with millisecond accuracy. This is accomplished with external response keys and an external clock that sends characters through the Macintosh’s serial port. For researchers interested in cross-modal lexical priming tasks, a tachistoscopic slide shutter is incorporated to allow for accurately timed presentation of visual stimuli. Because the visual display and response keys are external to the computer, display and reaction times are not subject to the timing constraints inherent to the keyboard or the Macintosh Event Manager. All circuit diagrams and code are in the public domain.

Mechanisms Leading to Single Event Upset

SRAM cell recovery time following a 140 MeV Krypton strike on a Sandia SRAM is modelled using a two-dimensional transient numerical simulator and circuit code. Strikes at both n- and p-channel off drains are investigated. Four principle results are obtained. The recovery time after a strike is strongly dependent on the drive of the restoring transistor. A struck off p-channel drain-to-gate capacitive coupling has a significant effect on recovery in SRAM with feedback resistors. Recovery time is approximately linear with LET over LET in the range to 0.4 pC/?. Finally, an experimental n-channel SEU has been observed in a Sandia SRAM without feedback resistors.

A new upper bound for the length of snakes

Ad-dimensional circuit code of spreads is a simple circuitC in the graph of thed-dimen sional unit cube with the property that for any verticesx andy ofC which differ in exactlyr co-ordinates,r<s, there exists a path fromx toy consisting ofr edges ofC. This property is useful for detecting and limiting errors. In this paper we give a new upper bound for the maximum length of ad-dimensional circuit code of spread 2.

Demonstration of a Time-Domain Integrated Electromagnetic-Field Circuit-Analysis Program

A numerical approach for combining an explicit time-domain electromagnetic computer code with an implicit time-domain circuit code is described. The numerical approach is then demonstrated by predicting plane-wave excitation of a loaded thin wire and the mutual coupling of two thin wires in a box separated by a conductive surface with an aperture. Possible applications to EMC problems are discussed.

Some new bounds for the maximum length of circuit codes (Corresp.)

A <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</tex> -dimensional circuit code of spread <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</tex> is a simple circuit <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</tex> in the graph of the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</tex> -dimensional unit cube with the property that for any vertices <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</tex> of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</tex> that differ in exactly <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</tex> coordinates <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r &lt; s</tex> , there exists a path from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</tex> consisting of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</tex> edges of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</tex> . Some new lower bounds will be given for the maximum length of a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</tex> -dimensional circuit code of spread <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</tex> for some values of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</tex> and for <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s = 4, s = 6</tex> , and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s = 7</tex> .

Collection of Charge on Junction Nodes from Ion Tracks

The collection of charge from ion tracks can produce logic upset and memory change in high density integrated circuits. It has been experimentally observed that drift conduction usually plays a dominant role when the ion track penetrates a junction. The first charge collection analysis concentrated on the diffusion conduction process. A recent analysis emphasizes drift conduction and describes the which produces drift collection from the substrate. The funneling phenomenon has been modelled using two-dimensional computer simulations. It is extremely desirable to develop analytical solutions tp better understand the problem and to provide the basis for modelling the effect in circuit and system analysis computer codes such as SYSCAP. This paper develops an approximate analytic solution expressed as I(t) = Io [exp(-?t) - exp (-st)] (1) where Io is approximately the maximum current, 1/? is the collection time constant of the junction, and 1/s is the time constant for initially establishing the ion track. The junction time constant is shown to be K?o/q?ND, and it increases slowly with funnel length when a funnel is present. The analysis shows that the excess carriers move almost exclusively by ambipolar diffusion for very early times, and that the fields present in semiconductor devices, including p-n junction fields, collapse. Ambipolar diffusion proceeds until the excess carrier concentration is reduced to approximately the background doping density at which time the junction field is restored and the carriers move by drift.

Evaluation of Short-Circuit Strength of Distribution Transformers

The revised ANSI short circuit (S.C.) code adopted in January, 1978, recognized that systems are getting so powerful that short circuit requirements of transformers needed revision. Manufacturers had to retest units under this revised code. However, since these tests are very expensive to make and destructive in nature, some technique needed to be developed to assure customers that production line units, which could vary considerably from the units actually tested, would also meet the requirement.

Theoretical and Scale Model EMP Response Analysis of Interconnected System Cables

A technique for calculating the EMP response of complex networks of coaxially shielded cables has been demonstrated for a generic system. A circuit code was employed at the systems level, but parameters used in the circuit code were determined and verified both by a more elaborate theoretical cable response code and by scaled experimental measurements. Details of the system level circuit code development are presented along with comparisons between the calculated and experimental responses.